Photographic developer



Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE PHOTOGRAPHIC DEVELOPER No Drawing. Application May 11, 1935, Serial No. 20,985. In Germany May 19, 1934 2 Claims.

Our present invention relates to a photographic developer.

One of its objects is a new photographic developer. Another object is a photographic developer which can be used without alkali. Further objects will be seen from the detailed specification following hereafter.

2-methylaminopheno1 is a known photographic developing agent. This substance, when compared with Metol and other rapid developing agents, has only a moderate capacity for developing and yields flat pictures lacking clearness. Consequently 2-methylaminophenol has been brought into the trade in admixture with other developing agents of more energetic action, for instance in admixture with hydroquinone under the name Ortol.

This invention relates to a photographic developer having a considerably enhanced developing capacity as compared with ortol owing to the presence of Z-methylaminophenol in which an alkyl-group, a hydroXy-group or an alkoxy group such as a methoxy group has been introduced as a substituent in the nucleus. These substitution products resemble Metol in their behavior, some representatives of the group surpassing it, however, in many properties, particularly in respect of preventing fog. In the case of the alkoxy-derivatives the reducing capacity is so much enhanced that development without alkali is possible. These bodies can be made from substituted 2-methylbenzoxazole-dimethyl sulfates by decomposition with caustic soda lye and saponification of the acetyl product thus obtained by means of hydrochloric acid.

The following are examples of suitable developers which surpass Metol in respect of the production of pictures free from fog:

Example 1 200 cc. of Water 1 gram of 4-methyl-2-methylaminophenol 5 grams of sodium sulfite (anhydrous) 10 grams of potassium carbonate 0.2 gram of potassium bromide.

Example 2 200 cc. of water 1 gram of 5-methoxy-Z-methylaminophenol 5 grams of sodium sulfite (anhydrous) 0.2 gram of potassium bromide.

What we claim is:

WILHELM SCHNEIDER. GUSTAV WILMANNS. 

